Prevalence of HIV, syphilis, and assessment of the social and structural determinants of sexual risk behaviour and health service utilisation among MSM and transgender women in Terai highway districts of Nepal: findings based on an integrated biological and behavioural surveillance survey using respondent driven sampling

Abstract Background Men who have sex with men (MSM) and transgender people are disproportionately affected by HIV and sexually transmitted infections. MSM and transgender people in Nepal experience considerable discrimination and marginalisation, they are subject to abuse from legal authorities and suffer from mental health issues. These social and structural factors can lead to increased sexual risk behaviour, barriers to accessing health care and result in adverse health outcomes. This study aims to assess the prevalence of HIV and syphilis, and how individual and socio-structural factors influence sexual risk behaviour and health care service uptake, among MSM and transgender women in the Terai highway districts of Nepal. Methods A cross-sectional survey was conducted in June 2016 in eight Terai highway districts of Nepal, recruiting 340 MSM and transgender women through respondent driven sampling. The primary outcome variables were HIV and syphilis prevalence. The secondary outcome variables were sexual risk behaviour and health care service uptake. Logistic regression models were used to assess the individual and socio-structural determinants of sexual risk behaviour and health care service uptake. Results The prevalence of HIV among MSM was 5%, whereas it was 13% in transgender women. The prevalence of active syphilis was 4% in MSM and 11% among transgender women. Among transgender women, 76% were involved in sex work, and 51% had experienced discrimination in one or more settings. In multivariable analysis, having visited an outreach centre was positively associated with condom use in the last sexual encounter among both MSM (AOR: 5.37, 95% CI: 2.42–11.94, p